Incinerator

ABSTRACT

An incinerator consists of a vertical shaft, a tube for the supply of combustion air extending into the shaft from the top of the incinerator, an exhaust gas tube extending coaxially inside the combustion air supply tube. The material to be combusted is supplied from the top of the shaft. The ashes descend through the shaft onto a rotary ash platform. Combustion air is also supplied to the ashes on the ash platform, penetrating through said ashes up into the burning material in the shaft.

United States Patent Danielsson et al.

[ 51 3,680,503 51 Aug. 1,1972

[54] INCINERATOR [72] Inventors: Gunnar Danielsson, Tystberga; Knut Ludvig Winquist, Orebro, both of Sweden 22 Filed: Sept. 29, 1970 21 Appl.No.: 76,368

[30] Foreign Application Priority Data Oct. 2, 1969 Sweden ..13585/69 [52] U.S. Cl ..-..1l0/l3, 110/18 R, 110/29 [51] Int. Cl F23g 5/00 [58] Field of Search ..1 10/13, 18,8, 36, 29

[56] v References Cited UNITED STATES PATENTS 2,452,844 1 1/ 1948 Esnaulte-Pelterie ..110/29 647,432 4/1900 Whedon ..1 10/13 X 669,632 3/1901 Gorman ..1 l0/ 1 3 2,452,843 1 1/1948 Esnaulte-Pelterie ..1 10/29 3,043,249 7/1962 Hebert et al. ..1lO/8 A Primary Examiner--Kenneth W. Sprague Attorney-Pierce, Scheffler & Parker 5 7] ABSTRACT An incinerator consists of a vertical shaft, a tube for the supply of combustion air extending into the shaft from the top of the incinerator, an exhaust gas tube extending coaxially inside the combustion air supply tube. The material to be combusted is supplied from the top of the shaft. The ashes descend through the shaft onto a rotary ash platform. Combustion air is also supplied to the ashes on the ash platform, penetrating through said ashes up into the burning material in the shaft.

3 Claims, 1 Drawing figure PATENTED M18 Y 1972 INVENTORS Kiwi Luclvfg \A/l'nquist Gunnar DanieLsson WE PcWkw Afliorn INCINERATOR The invention relates to an incinerator, particularly a refuse incinerator. The object of the invention is primarily to provide an incinerator in which material of the most varying types, including both combustible and incombustible material, can be completely burned so that neither the exhaust gases nor the ash contains unburned material. Another object of the invention is to achieve an incinerator having high combustion capacity per volume unit.

The incinerator according to the invention comprises a furnace shaft, an opening for the supply of material at the top of the shaft, a rotatable ash platform at the bottom of the shaft, means for removing ash from the ash platform, means for supplying combustive air to the shaft and means for removing exhaust gases from the shaft, and is characterized in that an obstacle is arranged in the shaft so that a space is formed in the material moving down in the shaft, and that the airsupply means are designed to supply air both in the form of primary air through the ash resting on the ash platform and also inthe form of secondary air to said space in the material.

The obstacle creating the space in the material may consist of a horizontal wall in the incinerator shaft. According to a preferred embodiment, however, the obstacle consists of the opening of a pipe acting either as supply-pipe for secondary air or as outlet-pipe for the exhaust gases. According to a particularly preferred embodiment the obstacle consists of two concentric pipes, the inner pipe being for the removal of exhaust gases and the outer one for the supply of combustive gas.

The invention will be further described with reference to the accompanying drawings with one example of an incinerator according to the invention.

The single FIGURE shows a vertical cross-sectional view of the incinerator.

The incinerator according to the drawings comprises a vertical sheetmetal cylinder 1 having an upper part 14 in which there is an opening 15 for pouring in the material 32 to be burned. The incinerator is provided with a refractory lining 2, the lower part 2a having a wall thickness which increases towards the bottom and forms a central passage 3 for the ash produced during the combustion. The lining rests on an annular metal sheet 16 which is welded to the wall 1.

A vertical shaft extends through the bottom 17 of the incinerator, the upper end of the shaft supporting a horizontal ash platform 4. The shaft 5 and the ash plat form 4 can be rotated by means of a motor 6 and gear transmission 20, 21. Above the ash platform at its periphery is a wiper 22, carried by a rod 23 which is displaceably journalled in the wall 1. The wiper can thus be inserted varying distances over the ash platform. Under the wiper 22 at the bottom 17 of the incinerator is an outlet funnel 7.

At least one opening 24 is arranged in the lower part of the incinerator. Air is supplied through this via a pipe 9 connected to a fan 8.

A pipe socket 25 is arranged centrally in the upper part 14 of the incinerator, through which a pipe 11 extends vertically down into the incinerator. The pipe 11 is provided with a branch 28 which communicates through a hose 29 and a pipe with the air-supply pipe 8. The pipe 11 can be fixed at the desired level in the incinerator with the help of a clamp ring 27 and a washer 26. A pipe 12a 12b extends coaxially in the pipe 11, the two parts being joined by means of flanges attached at a flange 30 at the upper end of the pipe 11. The opening 33 of the pipes 11, 12a forms an obstacle for the descending material 32, with the result that a space 13 is created in the material below this opening 33.

In the pipe 9 there is a damper 9a and in the pipe 10 a damper 10a. The air quantity can be regulated by means of these dampers so that there is a suitable distribution of the primary and secondary air. The primary air is supplied to the incinerator through the opening 24 and the secondary air through the annular gap 33 formed between the openings of the pipes 11, 12a.

The incinerator is also provided with at least one pipe 31 for the supply of additional fuel, in this case gas, in case the quantity of combustible material is not sufficient to maintain combustion. Broken lines in the drawing indicate suitable positioning of at least one pipe 31a for the supply of additional fuel in liquid form, for example waste oil.

During operation the air supplied through the opening 24, the primary air, will penetrate through the ash resting on the ash platform and on through the passage 3 up to the combustion zone 34 formed by the burning material. The primary air will be preheated as the ash is cooled.

The exhaust gases produced during the reaction between the primary air and the combustible material in the combustion zone and collected in the space 13 contain combustible constituents, such as carbon monoxide, and products originating from the destructive distillation of the combustible material. The exhaust gases have a high temperature, considerably exceeding their ignition temperature. A combustion of these gases is achieved by means of the secondary air supply through the gap between the pipes 11, 12a and the annular opening 33 to the space 13. This arrangement causes a strong turbulence in the space which results in intensive combustion and thus a sufficiently high temperature to make the combustion complete.

The coaxial pipes 11, 12, being mounted in a movable way, can be pushed down into the incinerator so that their lower ends are at the level giving the best combustion. If, owing to the high temperature, there is a melting of the pipes 11, 12 at their lower ends, this can be compensated for by pushing down the tubes into the incinerator a corresponding distance.

To start the incinerator gas is used which is supplied through the pipe 31. The ignited gas flows up through the opening 3 and is adjusted to such a quantity that its final combustion takes place in the material in the combustion zone 34. Similarly, gas may be supplied during operation if the material in the incinerator does not have a heating value enough to effect satisfactory combustion. Instead of gas liquid fuel may be used on such occasions, for example waste oil or the like. This is then supplied through the pipe 31a so that the material is saturated to a suitable extent by the oil and will thus burn satisfactorily.

The arrangement described above for the supply of additional fuel is well suited for automization. A thermo-couple element which senses the temperature in the combustion zone of the incinerator can then, by

means of suitable operating means, regulate the supply of extra fuel so that it is increased or decreased as the temperature in the combustion zone of the incinerator drops or rises, respectively.

It is important that the primary air is prevented from forming paths through the combustion zone 34 through channels and spaces which arise easily in ordinary fires, thus making it necessary to stir them. In the present incinerator construction this problem is avoided by the rotation of the ash platform since the pile of ash resting on the platform is also rotated. This means that a layer occurs in the combustion zone where ash particles and burning particles are subjected to stirring. This stirring also effectively separates the ash particles as they are formed, and good homogenity of the material in the combustion zone is thus obtained, this being a condition for uniform and satisfactory combustion. If desired the stirring effect can be increased by providing the ash platform with a member, for example a conical body, which projects from the platform to approximately the level of the passage 3. Besides the stirring of the material in the combustion zone of the incinerator mentioned above, the rotation of the ash platform 4 enables the ash to be continuously removed from the incinerator by the wiper 22 to the outlet funnel 7 at the bottom of the incinerator. Since the wiper is displaceable the removal of ash can be regulated to a suitable quantity.

The diameter of the ash platform 4 should suitably be such that a line 19 from the edge of the passage 3 to the edge of the ash platform forms an angle of 3045 with the horizontal plane, the angle of repose of the ash having thus been taken into consideration. The vertical distance between the metal sheet 16 and the ash platform is suitably once to twice the diameter of the passage 3.

What is claimed is: l. Incinerator, particularly a refuse incinerator, comprising a furnace shaft;

an opening at the top of the shaft for introduction of material to be burned;

a rotatable ash platform at the bottom of the shaft;

means for removing ash from the ash platform; a combustive air supply pipe extending vertically downwardly into the shaft, said combustive air supply pipe forming an obstacle to said material so as to form an open space in the material below the lower end of the combustive air supply pipe; an exhaust gas pipe extending inside of and coaxially with the combustive air supply pipe; there being an annular space between said two coaxial pipes;

means for supplying combustive air to said open space through said annular space;

means for supplying combustive air through any ash resting on the ash platform; and

means for vertically displaceably mounting said two coaxial pipes.

2. Incinerator according to claim 1, provided with means for the supply of additional fuel, characterized in that at least one pipe (31) for the supply of gas is arranged at the level of the ash resting on the ash platform.

3. Incinerator according to claim 1, provided with means for the supply of additional fuel, characterized ranged to pass through the furnace wall at a higher level than the space (13). 

1. Incinerator, particularly a refuse incinerator, comprising a furnace shaft; an opening at the top of the shaft for introduction of material to be burned; a rotatable ash platform at the bottom of the shaft; means for removing ash from the ash platform; a combustive air supply pipe extending vertically downwardly into the shaft, said combustive air supply pipe forming an obstacle to said material so as to form an open space in the material below the lower end of the combustive air supply pipe; an exhaust gas pipe extending inside of and coaxially with the combustive air supply pipe; there being an annular space between said two coaxial pipes; means for supplying combustive air to said open space through said annular space; means for supplying combustive air through any ash resting on the ash platform; and means for vertically displaceably mounting said two coaxial pipes.
 2. Incinerator according to claim 1, provided with means for the supply of additional fuel, characterized in that at least one pipe (31) for the supply of gas is arranged at the level of the ash resting on the ash platform.
 3. Incinerator according to claim 1, provided with means for the supply of additional fuel, characterized in that at least one pipe (31a) for the supply of liquid combustible material, for example waste oil, is arranged to pass through the furnace wall at a higher level than the space (13). 